1. Field of the Invention
The present invention relates to motor driven compressors incorporated in air conditioning systems.
2. Description of Related Art
Known motor driven compressors include a compressing mechanism and a motor, which includes a rotary shaft, which are located within a housing. The rotary shaft drives the compressing mechanism within the housing. In such motor driven compressors, a stator and a rotor, comprising the motor, may be positioned within the housing. An offset of phase between the stator and the rotor is set, and the rotor then is magnetized.
FIG. #8 depicts a partial cross-sectional view of a known motor driven compressor, as described in Japanese Patent Application Publication No. 09-45530.
Referring to FIG. #8, the motor driven compressor includes a;,direct current motor 102 and compressing mechanism (not shown), which is connected to direct current motor 102 via a rotary shaft 103 within a housing 101. Direct current motor 102 includes stator 104 and rotor 105. Stator 104 is fixed within housing 101, and rotor 105 is mounted on rotary shaft 103. Rotary shaft 103 is rotatably supported by bearing 120. Suction port 109 is formed within housing 101. A mark 108, such as crossing groove, is formed on a first end surface of rotary shaft 103. Housing 101 has a hole 106, which is positioned opposite a second end of rotary shaft 103. Hole 106 is closed by a sealing bolt 107.
In such known motor driven compressors, after direct current motor 102, rotary shaft 103, and compressing mechanism (not shown) are positioned within housing 101, the offset of phase between stator 104 and rotor 105 is set using a jig (not shown), such as a positioning member. Specifically, from outside housing 101, the jig (not shown) engages with mark 108 through hole 106. Subsequently, the jig is rotated around its axis to rotate rotary shaft 103 and rotor 105. Thereby, the phase offset between stator 104 and rotor 105 is set. Once in position, rotor 102 is magnetized. Finally, after magnetization, hole 106 is closed by sealing bolt 107. Magnetization occurs when current is provided to stator 104 via an electrical wire (not shown), which causes a magnetic force generated in stator 104 to act upon rotor 105.
In the known motor driven compressor described above, after magnetization, hole 106 of housing 101 is closed by sealing bolt 107. This configuration complicates such compressor""s structure by increasing the number of parts.
FIG. #9 depicts a partial cross-sectional view of another known motor driven compressor, as also described in Japanese Patent Application Publication No. 09-45530.
A mark 118 is formed on a first end surface of rotor 105 of direct current motor 102. Suction port 109 is formed within housing 101. Suction port 109 is positioned opposite mark 118. In this known motor driven compressor, after direct current motor 102 and compressing mechanism are installed and enclosed within housing 101, a jig (not shown) is inserted inside housing 101 through suction port 109. Subsequently, rotor 105 is rotated to offset the phase between stator 105 and rotor 104, so as to position mark 118 of rotor 105 opposite suction port 109. Finally, once mark 118 is in position, rotor 105 is magnetized.
In the known motor driven compressor described above, rotor 105 is machined with a mark, such as a hole. Therefore, this compressor has increased manufacturing costs and during machining, it is difficult to maintain the angle between rotor 105 and rotary shaft 103.
It is an object of the present invention to provide a motor driven compressor of structure, which allows the rotor to be readily magnetized, and which may reliably set the offset of phase between the rotor and stator for magnetizing the rotor.
It is an another object of the present invention to decrease the number of parts and to provide a motor driven compressor, in which the rotor need not be machined with a mark.
According to an embodiment of the present invention, a motor driven compressor has a motor and a compressing mechanism connected to the motor through a rotary shaft, which are located within a housing, and an offset of phase is set between a stator and a rotor. The rotor is mounted on the rotary shaft, which allows the rotor to rotate, so that it may be magnetized. Further, according to this embodiment, the housing of the motor driven compressor has a communication gas hole, which extends from a suction port to a discharge hole. Additionally, according to this embodiment, the motor driven compressor has a driving member driven together with the rotary shaft, and a mark positioned along a radial axis on a first end surface of the driving member. The mark is used for setting the offset of phase between the stator and the rotor on the basis of the mark, by positioning the mark opposite the suction port.
According to another embodiment of the present invention, a rotor in a motor driven compressor is magnetized by connecting a compressing mechanism to the motor through a rotary shaft, which are located within a housing, and setting the offset of phase between a stator of the motor and the rotor, where the rotor is mounted to a rotary shaft, allowing the rotor to rotate, so that it may be magnetized. Additionally, according to this embodiment, a driving member is driven together with the rotary shaft, and a mark is positioned along a radial axis on a first end surface of the driving for setting the offset of phase between the stator and the rotor on the basis of the mark, by positioning the mark opposite the suction port.
Other objects, features, and advantages will be apparent to persons of ordinary skill in the art in view of the following detailed description of the invention and the accompanying drawings.